Emulsified fat spreads, in particular margarines, provide certain consumer benefits, notably in taste properties. One important consumer benefit is its mouth texture. Factors which contribute to mouth texture are cooling impact, mouthmelt, and mouthfeel (cleanup). A preferred emulsified spread provides a significant cooling impact, a rapid, sharp melt sensation, and no coated or waxy feel on the tongue. Another important consumer benefit is the temperature cycling stability of the spread. During normal usage, margarines are repeatedly taken in and out of the refrigerator and are thus exposed to a frequent cycle of warmer and colder temperatures. Also, during storage and shipment, the spread can be subjected to temperature variation. Such temperature cycling can affect the properties of the spread, especially mouth texture. Preferred emulsified spreads will have temperature cycling stability, i.e. the ability to withstand temperature variation without significant adverse effects on its properties.
The spread should also satisfy certain consumer requirements. One important consumer requirement is spreadability. The spread should be sufficiently plastic so as to be easy to spread on softer foods such as bread or toast. Another more important consumer requirement, especially for stick-type products, is heat stability or resistance to slump. The spread should not lose its shape (slump) upon exposure to room temperatures for the period of time during which the spread is used. Preferred emulsified spreads will maximize the benefits of mouth texture and temperature cycling stability while at the same time satisfying the consumer requirements for spreadability and heat stability.
The emulsified spread normally used as the yardstick for all others, especially with regard to mouth texture, is butter. In standard butter manufacture, cream is separated from milk by centrifugation and then ripened to develop its flavor properties. The ripened cream is then churned at a temperature of from about 48.degree. F. (8.5.degree. C.) to 60.degree. F. (15.5.degree. C.). After churning, the buttermilk is drained off and the butter washed with water. The washed butter is worked and then packaged as tubs, cubes or prints. In a continuous process for making butter, the cream is heated to melt the fat completely with separation of the heated material to increase the fat content to above 80%. The higher fat material is reconstituted with milk, water, salt and color, and then emulsified, solidified in a continuous chiller, worked and packaged similar to standard margarine manufacture. See Bailey's Industrial Oil and Fat Products (3rd Ed. 1964), pp. 326-330.
Butter has a particularly pleasing mouth texture. The cooling impact on the tongue is significant and the mouthmelt rapid and sharp with no coated or waxy mouthfeel. The heat stability of butter is also adequate. However, refrigerated butter can be quite hard in consistency, especially after temperature cycling, and therefore difficult to spread on softer foods such as bread or toast. Thus, butter does not always satisfy the consumer requirements desired for emulsified spreads.
To improve the spreadability of the emulsified spread while still trying to approximate the mouth texture of butter, workers in the art have developed various margarines. One factor important to the spreadability and mouth texture of a margarine is the margarine fat used. These margarine fats need sufficient solids content to provide heat stability to the margarine at room temperature yet have sufficient plasticity to be spreadable when refrigerated. Such fats often contain a soft oil high in polyunsaturated fatty acids (linoleic and linolenic) such as safflower oil or sunflower oil. Also, blends of fats and oils are frequently used to formulate margarine fats.
Margarine fats are usually made from triglycerides which have predominantly long chain length fatty acids (e.g. palmitic, stearic, oleic and/or linoleic residues). These long chain fatty acid triglycerides can be interesterified to provide margarine fats having different melting profiles. See for example, U.S. Pat. No. Re. 30,086 to Carlisle et al, issued Aug. 28, 1979 (margarine fat consisting essentially of randomized palm oil); U.S. Pat. No. 3,889,011 to Read, issued June 10, 1975 (margarine fat containing palm oil or cottonseed oil co-randomized with soybean or sunflower oil); U.S. Pat. No. 3,634,100 to Fondu et al, issued Jan. 11, 1972 (margarine fat containing liquid oil such as sunflower or safflower and co-randomized blend of coconut oil, palm oil and palm stearine); U.S. Pat. No. 3,859,447 to Sreenivasan, issued Jan. 7, 1975 (margarine fat containing oils high in linoleic acid content such as sunflower oil and safflower oil which have been interesterified). More typically, the long chain fatty acid triglyceride is a hydrogenated (hardened) oil. See Bailey's Industrial Oil and Fat Products, supra, at page 339. Hydrogenation increases the solid content of the oil (more saturated triglycerides and conversion of at least some of the cis double bonds of the unsaturated fatty acid residues to trans double bonds), thus increasing the heat stability of margarine.
The spreadability, mouth texture, and to a lesser extent, the heat stability of the margarine can be affected by the processing conditions. In standard margarine manufacture, the aqueous phase ingredients (milk or milk solids, salt, flavors, preservatives and water) are dispersed in the oil phase (melted margarine fat, emulsifiers, color and flavors) and the mixture then sent through a scraped wall heat exchanger known as an A unit. Besides chilling the emulsified fat, the high local pressure and shearing action of the A unit induces fast nucleation and crystallization during the short residence time (ca. 5 to 10 seconds). The chilled emulsion is then sent to a crystallizer known as a B unit. Static B units in the form of a hollow pipe or resting tube normally provide firmer, stick-type margarines. Working B units in the form of picker boxes which serve to break up the larger fat crystals into smaller ones, normally provide softer, tub-type margarines. Because fats require crystallization times of 5 to 7 minutes (ca.), the residence time in the B unit is significantly longer than that of the A unit. The number and order of A and B units can be varied depending upon the characteristics desired for the margarine. See Haighton, "Blending, Chilling, and Tempering of Margarines and Shortenings", J. Am. Oil Chemists Soc., Vol. 53 (June, 1976), pp. 397-399 (especially flow diagram in FIG. 7); Wiedermann, "Margarine and Margarine Oil, Formulation and Control", J. Am. Oil Chemists Soc., Vol. 55 (Dec. 1978), pp. 823-829 (especially flow diagram in FIG. 5).
Most commercial margarines are sufficiently plastic when refrigerated to have satisfactory spreadability and have sufficient solids content to provide adequate heat stability at room temperature. However, commercial margarines, especially those containing hydrogenated oils, having mouthmelting properties which are flat or "thick" in character and leave a waxy or coated mouthfeel. Also, the temperature impact on the tongue does not provide the cooling sensation of butter. Thus commercial margarines lack the mouth texture of butter.
A number of methods have been developed which purport to formulate margarines having rapid mouthmelt properties. One example is U.S. Pat. No. 2,973,269 to Melnick, issued Feb. 28, 1961, which relates to a method for making a margarine product by super chilling the emulsion and then working the super-chilled emulsion to dissipate heat due to fat crystallization. In this method, one or more hydrogenated vegetable oils such as cottonseed or soybean oil are mixed with aqueous ingredients and then sent through one or more A units which discharge the emulsion at a temperature of from about 35.degree. F. (1.5.degree. C.) to 63.degree. F. (17.degree. C.) (more usually about 40.degree. F. [4.4.degree. C.] to 60.degree. F. [15.5.degree. C.]). The super-chilled emulsion is then sent to a working B unit where its temperature increases to about 50.degree. F. (10.degree. C.) to 73.degree. F. (22.5.degree. C.), preferably about 55.degree. F. (12.5.degree. C.) to 72.degree. F. (22.degree. C.). Preferably, the margarine discharged from the B unit is sent through another A unit which discharges the margarine at a temperature of from about 35.degree. F. (1.5.degree. C.) to 63.degree. F. (17.degree. C.).
Another example is disclosed in U.S. Pat. No. 3,488,199 to Gander et al, issued Jan. 6, 1960, which relates to a process for preparing a margarine product in which part of the fat is precrystallized. Referring to FIG. 1, a portion of the fat is mixed with aqueous ingredients at emulsifying pump 3 to form chiefly an oil-in-water emulsion. The remainder of the fat is cooled in A unit 13 to a temperature of less than 20.degree. C. (68.degree. F.), precrystallized in B unit 14 and then sent through two A units 15 and 16. The precrystallized fat from A units 15 and 16 at a temperature of about 5.degree. C. to 20.degree. C. (41.degree. F. to 68.degree. F.) is blended with the emulsion from pump 3 having a temperature of from 17.degree. C. to 23.degree. C. (45.degree. F. to 64.degree. F.) and then mixed in B unit 4. See also U.S. Pat. No. 2,772,976 to Schmidt et al, issued Dec. 4, 1956, which discloses a method for making a margarine product wherein the emulsion is precrystallized and then further chilled in two A units to a temperature of 40.degree. F. (4.degree. C.) prior to mixing with additional aqueous ingredients to form the ultimate margarine product.
Single fractionated or "topped" palm oil fats have also been used in formulating margarine products to improve mouth texture. U.S. Pat. No. 3,189,465 to Oakley et al, issued June 15, 1965 relates to a "cool tasting" margarine wherein at least a major proportion of the fat phase consists of one or more lower melting fractions of a semi-soft oil. These lower melting fractions can be obtained by a single thermal fractionation in which the higher melting fraction containing substantially all the trisaturated glycerides is removed. A representative example of such a fat phase consists of about 60 to 70% topped palm oil, about 15 to 25% lard (whole or topped), with the remaining fat being ground nut oil. Margarines formulated with the liquid fraction from a single thermal fraction of palm oil do not satisfy the consumer requirements for heat stability in a stick-type product. Also, margarines made from topped palm oil are extremely brittle and difficult to spread. See also U.S. Pat. No. 4,055,679 to Kattenberg et al, issued Oct. 25, 1977 (plastic fat suitable for margarines containing a palm-based fat such as palm olein co-randomized with fats such as soybean oil or safflower oil); U.S. Pat. No. 4,087,564 to Poot et al, issued May 2, 1978 (olein fraction obtained by single thermal fraction of co-randomized blend of palm oil and soybean oil).
Double fractionated palm oil fats are also known in the art as cocoa butter substitutes and extenders. One example is disclosed in U.S. Pat. No. 4,205,095 to Pike et al, issued May 27, 1980, which relates to a thermal fraction method for producing a palm mid-fraction suitable as a cocoa butter substitute or extender. Refined, bleached palm oil is heated (70.degree.-75.degree. C.) and then immediately cooled (28.degree.-33.degree. C.) to form a first liquid fraction (iodine value 55-60) and a first solid fraction (iodine value 38-44 and melting point 50.degree.-55.degree. C.). The first liquid fraction is separated, heated (60.degree.-65.degree. C.) and then immediately cooled (14.degree.-17.degree. C.) to produce a second liquid fraction (iodine value 59-64) and the desired palm mid-fraction (iodine value 48-53 and melting point 32.degree.-36.degree. C.) which is disclosed as having about 83% by weight symmetrical mono-unsaturated triglycerides and asymmetrical di-unsaturated triglycerides combined. The palm mid-fraction is separated and then hydrogenated to an iodine value of 38-45 to provide a hydrogenated palm mid-fraction having a melting point of 33.degree.-36.degree. C.
Another such example is disclosed in British Patent Specification No. 827,172 to Best et al, published Feb. 3, 1960, which relates to a method for making a cocoa butter substitute by a two-step solvent fractionation of palm oil.
It is an object of the present invention to provide a margarine or other emulsified spread having a desirable mouth texture and temperature cycling stability.
It is another object of the present invention to provide a margarine or other emulsified spread having satisfactory spreadability and heat stability, especially for stick-type products.
It is yet another object of the present invention to provide a margarine or other emulsified spread which provides consumer benefits in terms of mouth texture and temperature cycling stability while at the same time satisfying consumer requirements for spreadability and heat stability.
It is yet a further object of the present invention to provide a margarine which can be made from double thermally fractionated palm oil.
These and further objects of the present application are hereinafter disclosed.